Automatic fuel feed control for internal combustion engines



Oct l0, 1939. H. c. EDWARDS 2,175,458

AUTOMATIC FUEL FEED CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Aug. 14, 1937 2 Sheets-Sheet l 5g/6 I C 11/ Oct. 10, 1939. H. @EDWARDS 2,175,458

AUTOMATIC FUEL FEED CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Aug. 14, 1937 2 Sheets-Sheet 2 FOLB VACUUM /N MIC/YES OF MERCURY "Y, o j 56 .f6/M 54,26% E" Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE AUTOMATIC FUEL FEED CONTROL FOR INTERNAL CONIBUSTION ENGINES Application August 14, 1937, serial No. 159,035

1o claims. (C1. 12s- 140) This invention relates principally lto fuel injection systems for internal combustion engines of the type wherein the fuel is supplied to the engine by a pump operated by and in unison therewith and the quantity of injected fuel is automatically controlled according to the variation of the vacuum in the inlet manifold of the engine at different speeds thereof.

The invention has for its principal objects to provide for adjusting the vacuum for proper idling speed independently of the adjustment obtained by the main throttle valve, to` provide for accurately metering small quantities of fuel at idling speed, to obtain a proper initial adjustment of the fuel metering device relative to the governor, to provide an adjustable stop for limiting the maximum feed of the m-etering device and to provide for simplicity and compactness of ,construction and economy of design.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is a side elevational View of a Diesel engine air inlet manifold and fuel pump provided with an automatic fuel feed control embodyingmy invention,

Fig. 2 is a view looking at the governor end of the fuel pump,

Fig. 3 is a vertical central longitudinal section through the governor on the line 3--3 in Fig. 2,

Fig. 4 is a horizontal central longitudinal section on the line 4--4 in Fig. 3,

Fig. 5 is a perspective view of the divided or forked arm for manually shutting o the fuel supply and' for cooperating with the adjustable stop which limits the maximum quantity of injected fuel, I

Fig. 6 is a transverse section through the ai inlet conduit or manifold at the butterfly valve and valved by-pass,

Fig. 'l is a vertical section through the by-pass on the line 'I-l in Fig, 6,

Fig. il is a central longitudinal section through said manifold on the line 8-8 in Fig. 6,

Fig. 9 is a side elevation of the inlet end portion of the manifold, showing the adjustable stops for positioning the butterfly valve in its full throttle and idle throttle positions; and

Fig. l0 is a diagram illustrating in inches of mercury the manifold vacuum between full load and no load, and the speed of the engine in revolutions per minute at idling and full throttle positions of the butterfly valve ofthe intake manifold.

Fig. l of the accompanying drawings illustrates in side elevation an air inlet passageway or manifold A of a multi-cylinder internal combustion engine of the Diesel type and a multicylinder fuel feeding device or pump B for supplying accurately measured charges or liquid fuel to the respective'cylinders of said engine. As shown in Fig. 1, said pump comprises a housing I containing a shaft 2 that is operated by and in unison with the engine and has a separate tappet or cam 3 thereon for actuating the pump unit for 10 each working cylinder of the engine. vAs shown in Fig, l, said cam actuates a tappet cup 4 that is reciprocable in the pump housing I and, in turn, actuates a spring retracted plunger or piston 5 that reciprocates in a cylinder 6 provided 15 therefor in said housing.

The cylinder 6 is provided with two ports, an inlet port 'l and an overflow port (not shown); and a valved discharge passageway 9 leads from the compression chamber I0 of. said cylinder to 20 the engine cylinder supplied thereby. The pump plunger or piston 5 has an annular groove II therein that communicates with the compression chamber I0 of the cylinder 6 through a longitudinal groove I2, whereby delivery of the fuel 25 begins as soon as the plunger covers `the ports 1 and 8 and ends when the annular groove II of the plungerA is placed in communication with the overflow or bypass port 8. 'Ihe groove II is provided with a helical upper edge I3, whereby the 30 effective feed stroke of the plunger may be regulated by turning said plunger in its cylinder. The plunger turning mechanism comprises a rack I4 that is reciprocable in a horizontal bore provided therefor in the pump housing I and cooperates 35 with the teeth of a sleeve I5 that has an axial slidable but nonrotary connection with said plunger. This type of fuel injection pump is well vknown and it is considered unnecessary to illustrate it in detail.

'I'he quantity of `fuel delivered by the pump B is automatically controlled by a governor C that is operated by the vacuum in the engine inlet manifold A. Said governor comprises a housing I6 that is mounted on one end of the pump housing I and is provided with an expanding and contracting chamber I'I, the inner end wall of which is formed by a piston or diaphragmcomprising a metal disk I8 that is connected at its peripheral edge to the wall of said governor housing by means of a uid tight accordion or bellowslike member IBa of rubber or other flexible material that permits movement of said disk endwise of said housing and thus increases or decreases the volumetric content of said. chamber.

v'I'heeffective area of the diaphragm is equal to the area of the mean circle between the outside diameter of the bellows neck and the inside diameter of the governor housing, whereby a maximum area and travel of the`diaphragm may beobtained' with a governor housing of minimum dimensions.

A relatively light compression coil spring I9 is interposed between the disk or piston I8 and the outer end of said housing and tends to force said diskstoward the inner end of said pump housing and thus increase the volume of the governor chamber I1'. A relatively heavy spring 20 is mounted in a sleeve 2| that is threaded through the outer end of the governor housing in axial alinement but normally out of contact with the axially movable piston or disk I8. The sleeve 2| is provided with a nut 22 for loeking it inthe desired position of its axial adjustment.

As shown in Fig. 4,Athe control or rack rod I4 of the pump extends through an opening provided therefor in the inner end wall of the governor housing I6 and is connected by means of a cap screw 23 to a bracket member 24,which has a stud 25 that extends through a central circular opening in the disk I8 into the vacuum or pulsation chamber I1 where it is threaded to reeie a nut 26 for clamping said bracket to said Journaled in the governor housing I6 between the inner end wall thereof and the disk I8 is a horizontal rock shaft 21, one end of which extends outside of said housing and is provided with a rock arm 2B adapted to be movably operated by a suitable pull rod 29. Fixed to the rock shaft 21 within the governor housing I6 is a divided lever 30 having two upwardly extending arms 3| and 32, respectively. The arm 3| is adapted to bear against the rear end of the bracket 24 that connects the axial movable disk or end wall I8 of the expansible chamber I1 with the rack rod I4 of the pump. The other arm 32 of said lever is adapted to bear against an adjustable stop member in the form of a screw 33 that is threaded through the inner end wall of the governer hous ing I6 in abutting relation to said last mentioned other arm. The space in the governor housing between the inner end wall thereof and the vacuum chamber I1 is open to the atmosphere through an opening 34 in the bottom of said h ousing; and said chamber communicates with the inlet manifold A through a pipe or other suitable conduit 35.

Threaded on the inlet end of the engine manifold A is an elbow or angle fitting 36 that is provided '.vith a suitable air inlet valve 31. The suction pipe leading from the engine manifold A to the vacuum chamber I1 of the governor is connected by a nut 38 with the outer end of a nipple 39 which is threaded into a radial bore provided therefor in an outstanding flange 46 formed on the inlet end of the angle inlet fitting. A venturi 4I is mounted in the inlet end of the angle inlet fitting 36 and the nipple 39 extends through said venturi and opens into the bore thereof,

Located in the venturi 4| is a butterfly or throttle valve comprising a disk 42 mounted on a horizontal shaft 43 that extends through a diametral bore provided therefor in the flange 46 of the inlet fitting 36 at "right angles to the nipple 39 and substantially in the horizontal plane thereof. The shaft throttle valve 43 is journaled in bearings or bushings 44, 44a provided therefor in the inlet fitting 36 and extends exteriorly thereof where it is provided at one end with an arm 45 having a push-and-pull connection 46 with a suitable accelerator pedal or other actuating device (not shown). Said end of said butterlly valve shaft 43 is also provided with an arm 41 adapted to cooperate with a pair of adjustable stops in the form of screws 48 that are disposed one on each side of said shaft and are threaded through outstanding lugs 49 provided therefor on the inlet fitting 36 and are provided with lock nuts 50, When the arm 41 on the butteriiy valve shaft 43 is in contact with one of the stop screws 48, the butterfly valve 42 is n fully opened position; and when said arm is in engagement with the other stop screw, said valve is in a nearly Yclosed position with the nipple opposing side thereof disposed between the inner end of the nipple 39 and the inlet end of the angle fitting 36.

The nipple 39 is provided intermediate between the ends thereof with one or more radial ports 5| that open into an annular chamber 52 that surrounds said nipple and communicates with the inner end of a by-pass passageway or bore 53 that extends through the flange of said inlet fitting parallel to and substantially in the horizontal plane of the butterfly valve shaft 43. The outer end of the bore 53 is closed by means of a suitable plug 54; and a second bore or by-pass passageway 53a leads inwardly from the outer face of the angle fitting flange 46, intersects the bore 53 and opens into a radial port 55 of the buttery valve shaft supporting bushing or bearing 44a. 'I'he portion of the valve shaft 43 journaled in this bushing is provided with a longitudinal groove 56 adapted, in the throttling position only of the butterfly valve 42 to communicate at one end with the radial port 55 of said bushing. The other end of the longitudinal groove 56 opens into an annular space 51 provided therefor at the inner end of the bushing 44a; and said annular space opens into a vertical passageway 58 provided between the bore of the angle fitting and venturi. As shown in Fig. 8, the upper end of the vertical passageway 58 opens into the interior of the inlet fitting 36 between the inlet end thereof and the butterfly valve 42. The outer end of the bore or passageway 53a is closed by means of a threaded member 59 that terminates at its inner end in a needle valve portion 59a adapted to regulate the flow of air from the inlet side of the butterfly valve 42 to-the suction passageway, pipe or conduit 35 leading to the vacuum chamber governor.

'I'he fully opened or full throttle position of the buttery valve 42 provides an unrestricted inlet of air with the result that the vacuum in the engine manifold A is a minimum and rises very gradually when the speed of the engine is increased. In this full throttle position of 4the throttle valve 42, the vacuum in the engine manifold is insufficient to move the disk I8 against the pressure of the spring I9 with the result that the fuel control rack rod I4 of the pump is not actuated but remains in a position that will cause a maximum quantity of fuel to be delivered by the pump. As shown by the full throttle curve 66 on the diagram of Fig. 10, the vacuum rises very gradually with speed. In this diagram, the light horizontal lines indicate the manifold vacuum in inches of mercury; and two heavy horizontal lines marked Il and 62 indicate the range in manifold depression in changing from no load to full load; and the numbers at the base of said diagram indicate in hundreds the revolutions per minute of the engine shaft. The intersection of the curved line 60 with the horizontal full load line 62 indicates the maximum R. P. M. where the manifold f vacuum allows full throttle operation, i. e. 2560 R.' P. M. As the engine speed increases from this point to the point where the curve 60 intersects the horizontal no load line 6I, the manifold vacuum increases slightly and no load is reached at 2820 R. P. M. Thevertical distance between the horizontal full load lines 62 and no load line 6I in the diagram indicates the range of manifold vacuum in inches of mercury between full throttle position and no load position of the throttle valve. The main governor spring I9 is of such strength that it is fully extended at the point of intersection of the curve 66 with the full load line 62 so as to hold the control rod I4 in maximum fuel delivery position, and is fully compressed at the point of intersection of said curve with the no load linel so as to hold said control rod in minimum fuel delivery position. A different position of the throttle valve brings about a different range of speeds. For example, at throttle position as shown on the diagram by the curve 63, the speed range is from 1400 R. P. M. to 1750 R. P. M.

Also it is desirable, to vary the load on the main spring I9 to correctly position the control rod I4 of the pump which is attached to the diaphragm disk I8 to suit the maximum speed. This adjustment of the spring I9 is obtained by the use of shims I9a of varying thickness between the outer end of said spring and the outer end wall of the governor housing I6. By this arrangement, any degree of high speed vacuum can be accommodated to a particular desired maximum engine speed.

The idling vacuum produced when the throttle valve is in idle throttle position is approximately from 1%, to one inch mercury for satisfactory idling. Accordingly, it is desirable to put a certain amount of load on the engine when idling, in order to create stable idling conditions. Also, different makes of engines require different quantities of fuel to run idle at high and low speeds. Some engines may require more fuel at high speed than at low speed and others more fuel at low speed than at high speed. Accordingly, if more fuel is required at high speed, the vacuum at such speed must be less in proportion than the quantity of fuel required at low speed.

The idling condition is indicated on the diagram by the curve 64. Asindicated by this curve, full load speed is reached at the point where said curve intersects the horizontal full load line 62 and is approximately 390 R. P. M.; and no load speed is indicated at the point where said curve intersects the horizontal no load line 6I and-is approximately 425 R. P. M. When the engine has a suiiicient amount of manifold vacuum to produce stable running, this small variation in speed is diiiicult to control with the main spring I9. Accordingly, the heavier spring 20, which more nearly follows the slope of the vacuum curve 64, is brought into operation during the idling speeds. 'I'he heavier spring 20 acts as a bumper and surge spring and properly locates the diaphragm, disk I8 to accurately meter the small quantities of fuel required during idling. As shown on the diagram, thelowspeedidlingvacuum is exactly the same as the highspeed idling vacuum, which means that the spring 20 is also effective during high speed no load conditions and in effect increases the vertical distance between the curves 6I and 6 2. As the high speed range between full load and no load conditions should be kept as small as possible, the spring 20 should also be kept as weak as possible and still remain effective to stabilize low speed idling. In view of this condition, the throttle valve 42 is accurately set for idling position by means of one of the stops 48 to obtain the proper low speed idling vacuum. In order to adjust the vacuum to obtain the proper `suction in the governor chamber I'I for idling speed, the valve controlled by-pass 53, 53a, is brought into operation whenever the throttle valve 42 is moved into idling speed position. In this position of the throttle valve, the longitudinal groove 56 in the valve shaft 43 is placed in y communication with the' by-pass 53, 53a, thereby establishing communication between the governor chamber I'I and the portion of the intake manifold located between the inlet end thereof and said valve, so that the full vacuum brought about by the restriction ofthe manifold passageway by the valve is not fully effective at said governor chamber due to the additional amount of air supplied by said by-pass to the passageway leading to said chamber. By adjusting the needle valve 59 in the by-pass or auxiliary air supply passageway 53, 53a, the idling vacuum in the governor chamber II can be varied and adjusted to the spring 20, thereby making it possible to keep 'the governor adjustments at high speed separate from the governor adjustments at low speeds, by keeping the vacuum. at each of these speeds adjusted to produce the position of the control rod I4 required for pumping the proper quantity of fuel whether the idling quantity be greater or less than the high speed quantity.

The bracket 24, which connects the diaphragm i I disk I8 with the control rod I4 of the pump bears against the free end of the arm 3| of the forked lever 30, and said arm may be actuated by the control rod 29 so as to shift the diaphragm disk I8 outwardly' against the pressure of the spring 20 and thus operate the control4 rod I4 of the pump to shut off the supply of fuel. The other arm 32 of said lever bears against the stop screw 33, which can be adjusted to limit the opening movement of the control rod I4 and thus fix the maximum quantity of fuel which can be pumped` What I claim is:

l. In an automatic fuel feed control for an inf ternal combustion engine, an air inlet manifold, a throttle valve in said manifold, a fuel feeding device including a control member for regulating the quantity of fuel supplied by said device, a

vgovernor having a chamber which communicates with said manifold between said valve and said engine and has a movable wall operatively connected to said control member to reciprocate the same, a spring interposed between said movable wall of said chamber and the opposite Wall thereof for urging said control member to maximum fuel delivery position, means for adjusting the maximum fuel delivery position of said control member, and means in addition to said adjusting means for adjusting `the tension of said spring.

2. In an automatic fuel feed control for an4 with said movable wall for moving the latter against the pressure of said spring, an adjustabler between said valve and said engine and has a movable wall operatively connected to said rbd to reciprocate the same, a spring interposed between said movable wall of said chamber and the opposite wall thereof, a pivoted, manually operable arm cooperating with said movable wall for moving the latter against the pressure of said spring, a second arm movable with said first mentioned arm, an adjustable stop cooperating with said second arm for varying the maximum fuel delivery position of said rod, and means for adjusting the tension of said spring.

4. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold, a throttle valve in said manifold, a pump for sup- "plying fuel to said engine, a reciprocable rod associated with said pump for controlling the quantity of fuel supplied thereby, a governor having a chamber which communicates with said manifold between said valve and said engine and has a movable wall operatively connected to said rod to reciprocate the same, a spring interposed between lsaid movable wall of said chamber and the opposite wall thereof, means for manually moving said movable wall against the pressure of said spring, an adjustable stop for limiting the expansion of said spring, and adjusting shims interposed between one end of said spring and the adjacent end of said chamber for adjusting the tension of said spring to suit the conditions established by the position of the adjustable stop.

5. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold for said engine, a throttle valve in said manifold, a pump for supplying fuel to said engine, a control member associated with said pump for varying the quantity of fuel supplied thereby, a governor having a chamber which communicates with said manifold between said valve and said engine and has a movable wall operatively connected to said control member, a spring mounted in said chamber and bearing against said movable wall and the wall remote therefrom, a stop cooperating with said movable wall for limiting the expansion of said spring, a second spring mounted in said remote wall and adapted tolbe engaged by said movable wall at a predetermined point of its movement towards said remote wall, means for bodily adjusting said second spring towards and awa'y from said movable wall, said stop being adjustable to vary the maximum fuel delivery position of said control member, and means in addition to said adjustable stop for adjusting the tension of said rst mentioned spring.

6. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold for said engine, a throttle valve in said manifold, a pump for supplying fuel to said engine, a control member associated with said pump for varying the quantity of fuel supplied thereby, a governor having a chamber therein which communicates continuously with said manifold between said valve and said engine and has a movable wall operatively connected to said control member to operate the same, a spring interposed between said `movable wall of said chamber and the opposite wall thereof, a second spring mounted in said opposite wall and adapted to be engaged by said movable wall in the throttling position of said throttle valve, and means for establishing communication between said chamber and saidmanifold between the inlet end thereof and said valve during the throttling position only thereof.

7. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold for said engine, a throttle valve in said manifold, a

fuel pump for said engine, a control member associated with said pump for varying the quantity of f uel supplied thereby, a governor having a charnber that is in continuous communication with said manifold between said valve and said engine and has a movable wall operatively connected to said control member, and means operable only in the throttling position of said throttle valve for establishing communication between said chamber and said inlet manifold between the inlet end thereof and said throttle valve.

8. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold for said engine, a throttle valve in said manifold, a fuel pump for said engine, a control member associated with said pump for varying the quantity of fuel supplied thereby, a governor having a chamber with a movable wall operatively connected to said control member, a conduit communicating at one end with said chamber and at the other end with said manifold between said throttle valve and said engine, a passageway communicating at one end with said conduit and at the other with said manifold between the inlet end thereof and said throttle valve, and means operable by said throttle valve for cutting oif flow through said passageway except in the throttling position only of said throttle valve.

9. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold for said engine, a throttle valve in said manifold, a fuel pump for said engine, a control member associated with said pump for varying the quantity of fuel supplied thereby, a governor having a chamber with a movable Wall operatively connected to said control member, a conduit communicating at one end with said chamber and at the other end with said manifold between said throttle valve and said engine, a passageway communicating at one end with said conduit and at l the other end with manifold between the inlet end thereof and said throttle valve, a valve in said passageway for regulating the flow therethrough, and valve means operable with said throttle valve for cutting off flow through said passageway except in the throttling position only of said throttle valve.

10. In an automatic fuel feed control for an internal combustion engine, an air inlet manifold for said engine, a throttle valve in said manifold,

a fuel pump for said engine, a control member associated with said pump for varying the quantity of fuel supplied thereby, a governor having a chamber with a movable wall operatively' connected to said control member, a conduit communicating at one end-with said chamber and at the other end with said manifold between said throttle valve and the said engine, ashaft journaled in said manifold for operating said throttle valve, said shaft having a longitudinal groove ltherein in continuous communication at one end with said manifold between the inlet end thereof and the throttle valve therein, and a passageway communicating at one end with said conduit, the other end of said groove being adapted to communicate with the other end of said passageway in the throttling position only of said throttle to thereby establish communication between said conduit and said manifold between the inlet end HERBERT C. EDWIARDS. 

